Dorel Banabic | Technical University of Cluj-Napoca (original) (raw)

Papers by Dorel Banabic

History of mechanism and machine sciense, Dec 18, 2023

History of mechanism and machine sciense, Sep 21, 2023

Journal of physics, Jul 1, 2018

History of Romanian Technology and Industry

The Romanian Journal of Technical Sciences. Applied Mechanics., Sep 20, 2021

Encyclopedia of Aluminum and Its Alloys, 2019

Anisotropy is a key feature of the plastic behavior of aluminum alloy sheets. Significant researc... more Anisotropy is a key feature of the plastic behavior of aluminum alloy sheets. Significant research efforts have been dedicated during the past few decades to characterize and model this behavior. Advanced anisotropic yield criteria are available today in the scientific literature. This article reviews the most important yield criteria, in historical order, with an emphasis on the models particularly adapted to aluminum alloys. Along with the mathematical description, illustrations of their performance are provided together with the parameter identification procedure and the required input data. The mechanical parameters that describe plastic anisotropy are also summarized. The relevance of the available models for practical applications is analyzed, and guidance is provided for the selection and aware use of these yield criteria in engineering.

Manufacturing Engineering, 2000

A new yield criterion, derived from the Hosford criterion, is investigated. The new yield criteri... more A new yield criterion, derived from the Hosford criterion, is investigated. The new yield criterion is compared to experimental data for steel and aluminum sheets, respectively. The yielding predictions of this criterion are also compared to those provided by the Hill’s family criteria. It appears that the new yield criterion can predict the yielding behavior better than the Hill’s family. In the range of definition of the Hill’93 criterion, it has a similar user-friendly (but homogeneous) mathematical form and identification procedure.

Journal of Materials Processing Technology, 2019

Journal of Physics: Conference Series, 2016

Multiscale Modelling in Sheet Metal Forming, 2016

An elastic-viscoplastic model of McCormick type incorporating dynamic strain ageing and negative ... more An elastic-viscoplastic model of McCormick type incorporating dynamic strain ageing and negative strain-rate sensitivity is considered. A methodology for the identification of the unstable Portevin–Le Chatelier (PLC) range of strain-rates and mechanical parameters is considered by using a bifurcation analysis of spatial homogeneous processes. A critical condition on material parameters for the PLC effect is established. The loss of homogeneity and strain localization phenomena are investigated numerically for both constant strain-rate and constant stress-rate experiments. The sensitivity of the model to the mode of testing is analyzed. The influence of the testing machine is not taken into account by adding a machine equation, but by considering mixed stress- and strain-controlled boundary conditions. A discussion and comparison with existing models in literature is provided.

History of mechanism and machine sciense, Dec 18, 2023

History of mechanism and machine sciense, Sep 21, 2023

Journal of physics, Jul 1, 2018

History of Romanian Technology and Industry

The Romanian Journal of Technical Sciences. Applied Mechanics., Sep 20, 2021

Encyclopedia of Aluminum and Its Alloys, 2019

Manufacturing Engineering, 2000

Journal of Materials Processing Technology, 2019

Journal of Physics: Conference Series, 2016

Multiscale Modelling in Sheet Metal Forming, 2016

The paper deals with constitutive modeling of highly anisotropic sheet metals and presents FEM ba... more The paper deals with constitutive modeling of highly anisotropic sheet metals and presents FEM based earing predictions in a round cup drawing simulation of highly anisotropic aluminum alloys where more than four ears occur. For that purpose the BBC2008 yield criterion, which is a plane-stress yield criterion formulated in the form of a finite series, is used. Thus defined criterion can be expanded to retain more or less terms, depending on the amount of given experimental data. To be used in sheet metal forming simulations the constitutive model, derived in accordance with the associated flow theory of plasticity, has been implemented in a general purpose finite element code ABAQUS/Explicit via VUMAT subroutine, considering alternatively different number of parameters in the BBC2008 yield criterion, where possible number of parameters are any multiple of number 8. For the integration of the constitutive model the explicit NICE (Next Increment Corrects Error) integration scheme has been used. The CPU time consumption for an explicit deep drawing simulation, which is based on the developed constitutive model, has been proven to be, due to effectiveness of the used integration scheme, fully comparable to the performance experienced when the simulation is performed with ABAQUS built-in constitutive models and implicit integration schemes. Two aluminum alloys, namely AA5042-H2 and AA2090-T3, have been considered for a validation of the constitutive model. The respective BBC2008 model parameters have been identified for both alloys with a developed numerical procedure, based on a minimization of the specified cost function. For both materials, the simulation predictions based on the BBC2008 model prove to be in very good agreement with the experimental results. Further, in order to show the flexibility of the BBC2008 model in modeling of highly anisotropic sheet metal response, we have introduced a highly anisotropic fictitious material which yields, according to the theory, twelve ears in cup drawing. As it is shown in the paper the BBC2008 model is able to predict twelve ears in cup drawing simulation with the formulation containing 16 parameters for anisotropy description only. The flexibility and accuracy of the constitutive model together with the robust identification and integration procedure guarantee the applicability of the BBC2008 yield criterion in industrial applications. Ó 2013 Published by Elsevier Masson SAS. 1. Introduction Numerical simulation has become an important analysis tool in the manufacturing processes design. By shortening both the time required in the D&R stage and the time needed for a corresponding production implementation it contributes significantly to reducing the overall production costs and failure rate. Becoming in this regard indispensable, this computational instrument has extended during the last decades its applicability to various industrial fields. The consistency of the decisions made on the numerical simulation basis is highly dependent on the attained degree of the physical objectivity and numerical accuracy of the simulation. Many researchers involved in this domain focused consequently their efforts on improving both the quality of the theoretical models implemented in the simulation programs and efficiency of there applied computational strategies. Extensive past research performed in the field of sheet metal forming processes has proven that the adopted constitutive models have a strong influence on the reliability of the obtained numerical simulation results. In this paper we are analyzing, referring to the earing and height of